The present invention relates to a disinfectant substance comprising an iodine (impregnated) resin and to a process for the preparation thereof. The iodine/resin disinfectant may be used to sterilize a fluid such as, for example, water, air, as well as fluid exudate secreted at body lesions or traumas such as at cuts, burns, etc.; thus, the disinfectant may be used to devitalize microorganisms (e.g. bacteria, viruses, etc.) which may be present in the fluid (e.g. water, air, pus and the like). The treatment of fluid, such as water or air, with an iodine/resin disinfectant of the present invention may leave behind non-detectable (or acceptable) residual diatomic iodine in the fluid (e.g. water or air). The present invention in particular relates to a demand type broad spectrum resin-polyiodide (e.g. water, air, wound) disinfectant.
Diatomic halogen (such as I2, Cl2, Br2, etc.) has traditionally been used to disinfect water. Diatomic chlorine, for example, is a widely exploited disinfectant for controlling or eliminating micro-organisms which may be present in water. A disadvantage of a sterilization regime which exploits diatomic halogen is that the regime may leave behind unacceptable (residual) levels of halogen in the water once sterilization is complete.
An iodine/resin product has, however, been proposed for use as a demand disinfectant, namely a disinfectant wherein iodine is released almost entirely on a demand-action basis. U.S. Pat. Nos. 3,817,860, 3,923,665, 4,238,477 and 4,420,590 teach such a demand disinfectant wherein iodine is the active disinfectant agent; the entire contents of each of these patents is incorporated herein by reference. In accordance with the teachings of these patents the resin product may be used without fear of introducing unacceptable concentrations of diatomic iodine into the water to be sterilized.
U.S. Pat. Nos. 3,817,860 and 3,923,665 teach an iodine/resin demand disinfectant which is the reaction product obtained by contacting a strong base anion exchange resin with a suitable source of triiodide ions. The reaction product is taught as being very stable in the sense that the amount of iodine (e.g. I2) released into water from the reaction product is sufficiently low that the water disinfected thereby is immediately ready for use, ie. as drinking water.
In accordance with the teachings of U.S. Pat. Nos. 3,817,860 and 3,923,665 the procedure for preparing the iodine/resin comprises forming a triiodide ion (solution or sludge) by dissolving diatomic iodine in a water solution of a suitable alkali metal halide (e.g. KI, NaI, . . . ). The triiodide solution is in particular taught as being made with a minimal (i.e. minor) water content just sufficient to avoid causing the I2 to crystallize out; see example 1 of U.S. Pat. No. 3,923,665. The resulting (solution) containing the triiodide ion is then contacted with the starting resin (under ambient conditions with respect to temperature (i.e. 25 to 30xc2x0 C.) and pressure), the triiodide ions exchanging with the anion of the resin (e.g. exchange with chlorine, sulfate, etc.,). The starting resin is taught as being a porous granular strong base anion exchange resin having strongly basic groups in a salt form wherein the anion thereof is exchangeable with triiodide ions. In accordance with the teachings of the above prior art references contacting is continued until the desired amount of triiodide has reacted with the strongly basic groups such that bacterially contaminated water is disinfected when passed through a bed of the obtained resin. After a suitable contact time the iodine/resin is (water) washed to remove water-elutable iodine from the resin product.
However, as indicated in U.S. Pat. No. 4,238,477, it is difficult to use the procedures outlined in the two previously mentioned U.S. patents so as to obtain a homogeneous iodine/resin product containing only triiodide anions and wherein all of the active sites of the resin have been converted to triiodide ions.
Accordingly, U.S. Pat. No. 4,238,477 teaches an alternate process whereby the iodine/resin may be produced. In accordance with this alternate impregnation/contact process, a suitable resin in the iodide form (Ixe2x88x92) is contacted with water comprising diatomic iodine (I2) in solution, the water being recycled between a source of a predetermined amount of diatomic iodine and the resin. The process as taught by this latter patent, however, is a relatively complicated system of pumps, vessels, heaters, etc.; by exploiting a fluidized bed, it in particular may lead to a significant degree of resin bead attrition, i.e. particle breakup.
The processes as taught in U.S. Pat. Nos. 3,817,860 and 3,923,665 are carried out at ambient temperature and ambient pressure conditions. The U.S. Pat. No. 4,238,477 teaches that the contact may occur at a higher temperature such as 60 to 950xc2x0 C. but that the temperature must be a non-boiling temperature (with respect to water); see column 3 lines 55 to 66.
The above referred to U.S. patents teach the use of the demand disinfectant iodinated resins for treating water; see also U.S. Pat. Nos. 4,298,475 and 4,995,976 which teach water purification devices or systems which exploit iodinated resins. None of these patents teaches the use of the iodinated resins for the purpose of sterilizing air.
It is also known to use iodine tincture for sterilising wounds. The sterilisation effect of iodine tincture is short lived; this means that the tincture must be reapplied on a regular basis to maintain the sterilisation effect. However, such solutions may also damage or destroy the tissue around the wound if applied too liberally and too often. Additionally, the direct application of such solutions to a lesion or wound is usually accompanied by a painful sensation.
Accordingly it would be advantageous to have an iodine/resin product which has improved characteristics over known or commercially available iodine/resin disinfectant products.
It would also be advantageous to have an alternate process for the preparation of a iodine/resin product (which has improved characteristics over the previously known iodine/resin).
It would be advantageous to have an alternative effective demand disinfectant (e.g. bactericidal) resin and an effective technique for the manufacture thereof. It would, in particular, be advantageous to have an iodine/resin demand disinfectant having a relatively low level of iodine bleed into a fluid (such as water or air) being treated as well as an iodine impregnation process for obtaining such iodinated resin.
It would also be advantageous to have a means whereby lesions, such as for example wounds or burns, may be treated in order to facilitate healing by devitalising microorganisms which may already be in the area of the lesion and further to prevent microorganisms from having access to such lesion (i.e. a dressing), i.e. to inhibit access from any outside biovectors such as for example airborne, waterborne, spital borne, blood borne, particulate borne microorganisms and the like.
It would additionally be advantageous to have a means for inhibiting or preventing microorganisms from contacting predetermined areas of the body such as the skin (e.g. a protective textile for making protective clothing).
In accordance with a general aspect, the present invention provides a process for preparing a demand disinfectant resin, said disinfectant resin being an iodinated strong base anion exchange resin, (i.e. a demand disinfectant-resin comprising polyiodide ions, having a valence of xe2x88x921, the ions being absorbed or impregnated into the resin as herein described) the process comprising a conversion step, the conversion step comprising contacting a porous strong base anion exchange resin in a salt form with a sufficient amount of an iodine-substance absorbable by the anion exchange resin such that the anion exchange resin absorbs said iodine-substance so as to convert the anion exchange resin to the disinfectant-resin, said iodine-substance being selected from the group comprising I2 (i.e. diatomic iodine) and polyiodide ions having a valence of xe2x88x921, characterized in that for the conversion step at least a portion of the absorption of iodine-substance is effected at elevated temperature and at elevated pressure, said elevated temperature being 100xc2x0 C. or higher (e.g. a temperature higher than 100xc2x0 C. such as, for example, 102xc2x0 C., 103xc2x0 C., 104xc2x0 C., 105xc2x0 C., 110xc2x0 C. 115xc2x0 C., 150xc2x0 C., etc.), said elevated pressure being greater than atmospheric pressure (e.g. a pressure greater than barometric pressure such as for example 2 psig, 3 psig, 4 psig, 5 psig, 15 psig, 25 psig, 35 psig, 100 psig, etc.).
In accordance with the present invention the disinfectant-resin may be one in which diatomic iodine is incorporated. The disinfectant polyiodide-resin may in particular be triiodide-resin. Thus, for example, the iodine-substance may comprise triiodide ion of formula I3xe2x88x92, i.e. so as to form a disinfectant-resin which comprises (absorbed) triiodide ions of formula I3xe2x88x92.
The terms xe2x80x9ctriiodidexe2x80x9d, xe2x80x9ctriiodide ionxe2x80x9d and the like, as used in the context herein, refer to or characterize a substance or a complex as containing three iodine atoms and which has a valence of xe2x88x921. The triiodide ion herein therefore is a complex ion which may be considered as comprising molecular iodine (i.e. iodine as I2) and an iodine ion (i.e. Ixe2x88x92). Similarly the terms xe2x80x9cpolyiodidexe2x80x9d. xe2x80x9cpolyiodide ionsxe2x80x9d and the like, refer to or characterize a substance or a complex as having three or more iodine atoms and which may be formed if more of the molecular iodine combines with the monovalent triiodide ion. These terms are more particularly described in the above referred to U.S. patents.
In accordance with a further aspect, the present invention provides a process for preparing a demand disinfectant resin, said disinfectant resin being an iodinated strong base anion exchange resin, (i.e. a demand disinfectant-resin comprising polyiodide ions, having a valence of xe2x88x921, the ions being absorbed or impregnated into the resin as herein described),
the process comprising a conversion step, the conversion step comprising contacting a porous strong base anion exchange resin in a salt form other than the iodide form Ixe2x88x92, with a sufficient amount of an iodine-substance absorbable by the anion exchange resin such that the anion exchange resin absorbs said iodine-substance so as to convert the anion exchange resin to the disinfectant-resin, said iodine-substance being selected from the group comprising polyiodide ions having a valence of xe2x88x921,
characterized in that for the conversion step at least a portion of the absorption of iodine-substance is effected at elevated temperature and at elevated pressure, said elevated temperature being 100xc2x0 C. or higher (e.g. a temperature higher than 100xc2x0 C.), said elevated pressure being greater than atmospheric pressure (e.g. a pressure greater than barometric pressure).
The strong base anion exchange resin may be in a salt form such as for example a chloride or hydroxyl form.
The conversion in accordance with the present invention may essentially or at least partially be effected at said elevated temperature and elevated pressure. The conversion, in accordance with the present invention, may, thus for example, be effected in one, two or more stages. For example, the elevated pressure/temperature conditions may be divided between two different pairs of elevated pressure/temperature conditions, e.g. an initial pressure of 15 psig and a temperature of 121xc2x0 C. and a subsequent pressure of 5 psig and a temperature of 115xc2x0 C.
If the conversion is to be carried out in two stages, it may for example, comprise a first stage followed by a second stage. The first stage may, for example, be effected at low temperature conditions (e.g. at ambient temperature and ambient pressure conditions) whereas the second stage may be effected at elevated conditions such as described herein.
Thus, the present invention, in accordance with another aspect provides a process for preparing a demand disinfectant resin, said disinfectant resin being an iodinated strong base anion exchange resin, (i.e. a demand disinfectant-resin comprising polyiodide ions, having a valence of xe2x88x921, the ions being absorbed or impregnated into the resin as herein described),
the process comprising a conversion step, the conversion step comprising contacting a porous strong base anion exchange resin in a salt form with a sufficient amount of an iodine-substance absorbable by the anion exchange resin such that the anion exchange resin absorbs said iodine-substance so as to convert the anion exchange resin to the demand disinfectant resin, said iodine-substance being selected from the group comprising 12 and polyiodide ions having a valence of xe2x88x921,
characterized in that said conversion step comprises an initial conversion stage followed by a second conversion stage, in that said initial conversion stage comprises contacting the anion exchange resin with the iodine-substance at a temperature of 100xc2x0 C. or lower so as to obtain an intermediate composition, said intermediate composition comprising residual absorbable iodine-substance and an intermediate iodinated resin, (i.e. a resin comprising absorbed polyiodide ions having a valence of xe2x88x921), and
in that said second conversion stage comprises subjecting the intermediate composition to elevated temperature and elevated pressure, said elevated temperature being 100xc2x0 C. or higher (e.g. a temperature higher than 100  C.), said elevated pressure being greater than atmospheric pressure.
In accordance with a further particular aspect, the present invention provides a process for preparing a demand disinfectant resin, said disinfectant resin being an iodinated strong base anion exchange resin, (i.e. a demand disinfectant-resin comprising polyiodide ions, having a valence of xe2x88x921, the ions being absorbed or impregnated into the resin as herein described),
the process comprising a conversion step, the conversion step comprising contacting a porous strong base anion exchange resin in a salt form other than the iodide form Ixe2x88x92 with a sufficient amount of an iodine-substance absorbable by the anion exchange resin such that the anion exchange resin absorbs said iodine-substance so as to convert the anion exchange resin to the disinfectant-resin, said iodine-substance being selected from the group comprising polyiodide ions having a valence of xe2x88x921,
characterized in that said conversion step comprises an initial conversion stage followed by a second conversion stage, in that said initial conversion stage comprises contacting the anion exchange resin with the iodine-substance at a temperature of 100xc2x0 C. or lower so as to obtain an intermediate composition, said intermediate composition comprising residual absorbable iodine-substance and an intermediate iodinated resin (i.e. a resin comprising absorbed polyiodide ions having a valence of xe2x88x921), and
in that said second conversion stage comprises subjecting the intermediate composition to elevated temperature and elevated pressure, said elevated temperature being 100xc2x0 C. or higher (e.g. a temperature higher than 100xc2x0 C.), said elevated pressure being greater than atmospheric pressure.
In accordance with the present invention, for the first stage, the low temperature may, for example, be a non-boiling temperature of not more than 95xc2x0 C.; e.g. 15 to 60xc2x0 C.; e.g. ambient temperature or room temperature such as a temperature of from about 15xc2x0 C. to about 40xc2x0 C., e.g. 20 to 30xc2x0 C. The pressure associated with the low temperature condition of the first stage may, for example, be a pressure of from 0 (zero) to less than 2 psig; the pressure may in particular be essentially ambient pressure (i.e. a pressure of less than 1 psig to 0 (zero) psig; 0 psig reflecting barometric or atmospheric pressure).
In accordance with the present invention, for the second stage, the elevated temperature may, for example, be: a temperature of 102xc2x0 C. or higher; e.g. 105xc2x0 C. or higher; e.g. 110xc2x0 C. or higher; e.g. 115xc2x0 C. or higher; e.g. up to 150xc2x0 C. to 210xc2x0 C.; e.g. 115xc2x0 C. to 135xc2x0 C. The elevated pressure associated with the elevated temperature condition of the second stage may, for example, be: a pressure of 2 psig or greater; e.g. 5 psig or greater; e.g. 15 psig to 35 psig; e.g. up to 100 psig.
The present invention further relates to any demand disinfectant resin, the disinfectant resin being an iodinated strong base anion exchange resin which is the same as an iodinated strong base anion exchange resin prepared in accordance with a process as defined herein; an iodinated resin the same as a resin prepared in accordance with the (particular) process described herein is one which has the same low iodine bleed characteristic, i.e. the iodine is (more) tenaciously associated with the resin than for previously known iodinated resins. It in particular relates to a demand disinfectant resin, the disinfectant resin being an iodinated strong base anion exchange resin whenever prepared in accordance with a process as defined herein.
The present invention also relates to the use of iodinated resins to disinfect fluids containing microorganisms, such fluids including air, water, pus, and the like. The iodinated resin may for example be a known resin such as discussed herein, a resin in accordance with the present invention, nylon based resin beads impregnated with iodine (such as MCV resin from MCV Tech. Intn""l Inc.), and the like.
Thus the present invention also provides a method for disinfecting air containing airborne microorganisms, said method comprising passing said air over a disinfectant resin such that airborne microorganisms contact said resin and are devitalized thereby, said disinfectant resin comprising an iodinated resin. The disinfectant resin may, for example, be a demand disinfectant resin. The disinfectant resin may, for example, comprise an iodinated strong base anion exchange resin.
The present invention further provides a system for disinfecting air containing airborne microorganisms, said system comprising
means for providing an air path for the movement of air there through, and
a disinfectant resin disposed in said air path such that airborne microorganisms in air passing through said air path are able to be brought into contact with said resin and be devitalized thereby,
said disinfectant resin comprising an iodinated resin. The disinfectant resin may, for example, be a demand disinfectant resin. The disinfectant resin may, for example, comprise an iodinated strong base anion exchange resin.
The present invention additionally provides a combination comprising
a disinfectant component and
a carrier component, said disinfectant component comprising particles of an iodinated resin,
said particles of said disinfectant component being held (e.g. fixed) to said carrier component. The disinfectant component may, for example, be a demand disinfectant component. The disinfectant resin may, for example, comprise an iodinated strong base anion exchange resin. The combination may be used as a means for providing a barrier or shield for the body against microorganisms. The combination may thus, for example, be incorporated into a textile or other wearing apparel starting material in the form of a layer (e.g. a liner layer). The obtained raw wearing apparel material may then be used to make a protective garment, glove, sock, footwear (e.g. shoe), helmet, face mask and the like; the obtained wearing apparel nay be worn in hazardous environments to protect the wearer from contact with viable microorganisms. The combination as desired or as necessary may flexible or stiff; depending on the nature of the carrier component and also on the form of the resin (e.g. plate, particle, etc.); the carrier component may comprise a (e.g. flexible) polymeric matrix. The carrier component may comprise a porous cellular matrix; particles of a demand disinfectant resin may be dispersed in a polymeric matrix. The iodinated strong base anion exchange resin may comprise a strong base anion exchange component which represents from 25 to 90 (e.g. 45 to 65) percent by weight of the total weight of the iodinated resin.
The present invention in particular provides a combination comprising a demand disinfectant component and a carrier component, said demand disinfectant component comprising particles of an iodinated strong base anion exchange resin, said particles being held to said carrier component, said iodinated strong base anion exchange resin comprising a strong base anion exchange resin component which represents from 25 to 90 percent by weight of the total weight of the iodinated strong base anion exchange resin.
The present invention further provides a combination comprising a demand disinfectant component comprising particles of an iodinated strong base anion exchange resin, and a carrier component comprising a polymeric matrix, said particles being dispersed in said polymeric matrix.
The present invention in a more particular aspect provides a sterilisation dressing, for being applied to a lesion, (such as a sore, a wound (e.g. cut), an ulcer, a boil, an abrasion, a burn or other lesion of the skin or internal organ), said dressing comprising
a disinfectant component and
a carrier component,
said disinfectant component comprising particles of an iodinated strong base anion exchange resin, said carrier component being configured so as to hold onto particles of said disinfectant component such that microorganisms are able to be brought into contact with said particles and be devitalised thereby, said carrier component being of a pharmaceutically acceptable material. The disinfectant component may, for example, be a demand disinfectant. The disinfectant resin may, for example, comprise an iodinated strong base anion exchange resin. The carrier component may be stiff or it may be flexible as desired. The (sterilization) dressing may, for example, be applied over a wound or burn and be held in place over the time period needed for the body to repair the damaged area; the dressing during this time will act not only as a barrier or shield to prevent infectious microorganisms from contacting the lesion but also to sterilize the immediate area around the lesion including sterilising any fluid exudate such as pus which may exude from the lesion. Surprisingly, it has, for example, been found that even with relatively prolonged exposure of (guinea pig) skin to the active element of the dressing (i.e. the demand disinfectant) no irritation or inflammation was noted. It has also surprisingly been found that the dressing may effect infectious agents deep beneath the skin or dressing. The healing process may thus be hastened by the application of a (sterilization) dressing in accordance with the present invention.
The demand disinfectant for the above mentioned method and system for treating air as well as for the combination and the dressing may be an iodinated resin produced in accordance with the present invention or it may be a known demand disinfectant iodinated resin such as for example as mentioned herein.
The demand disinfectant depending on the intended use may take on any desired form; it may be bulk form; it may be in sheet form; it may be in particulate or granular form (e.g. particles of resin of from 0.2 mm to 1 cm in size), etc.
It is to be understood herein, that if a xe2x80x9crangexe2x80x9d or xe2x80x9cgroup of substancesxe2x80x9d is mentioned with respect to a particular characteristic (e.g. temperature, pressure, time and the like) of the present invention, the present invention relates to and explicitly incorporates herein each and every specific member and combination of sub-ranges or sub-groups therein whatsoever. Thus, any specified range or group is to be understood as a shorthand way of referring to each and every member of a range or group individually as well as each and every possible sub-ranges or sub-groups encompassed therein; and similarly with respect to any sub-ranges or sub-groups therein. Thus, for example,
with respect to a pressure greater than atmospheric, this is to be understood as specifically incorporating herein each and every individual pressure state, as well as sub-range, above atmospheric, such as for example 2 psig, 5 psig, 20 psig, 35.5 psig, 5 to 8 psig, 5 to 35, psig 10 to 25 psig, 20 to 40 psig, 35 to 50 psig, 2 to 100 psig, etc.;
with respect to a temperature greater than 100xc2x0 C., this is to be understood as specifically incorporating herein each and every individual temperature state, as well as sub-range, above 100xc2x0 C., such as for example 101xc2x0 C., 105xc2x0 C. and up, 110xc2x0 C. and up, 115xc2x0 C. and up, 110 to 135xc2x0 C., 115xc2x0 C. to 135xc2x0 C., 102xc2x0 C. to 150xc2x0 C., up to 210xc2x0 C., etc.;
with respect to a temperature lower than 100xc2x0 C., this is to be understood as specifically incorporating herein each and every individual temperature state, as well as sub-range, below 100xc2x0 C., such as for example 15xc2x0 C. and up, 15xc2x0 C. to 40xc2x0 C., 65  C. to 95xc2x0 C., 95xc2x0 C. and lower, etc.;
with respect to residence or reaction time, a time of 1 minute or more is to be understood as specifically incorporating herein each and every individual time, as well as sub-range, above 1 minute, such as for example 1 minute, 3 to 15 minutes, 1 minute to 20 hours, 1 to 3 hours, 16 hours, 3 hours to 20 hours etc.;
and similarly with respect to other parameters such as low pressures, concentrations, elements, etc.
It is also to be understood herein that xe2x80x9cgxe2x80x9d or xe2x80x9cgmxe2x80x9d is a reference to the gram weight unit; that xe2x80x9cCxe2x80x9d is a reference to the Celsius temperature unit; and xe2x80x9cpsigxe2x80x9d is a reference to xe2x80x9cpounds per square inch gaugexe2x80x9d.